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Oct. 23, 1928.

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BY 0 ATTORNEY Oct. 23, 1928. r 1,688,943

s. T. SCHOFIELD RADIO RECEIVING APPARATUS Filed 001:. 4, .1927 3 ShOOtQ-ShBGt 3 :EI= E IIETa- E IN VEN TOR. fiamzwZ {54276916 id d ATTORNEY Patented Oct. 23, 1928.

UNITED STATES PATENT OFFICE.

amour. manor. scnomnn, on WASHINGTON, msrnrcr or common, assreNon T NATIONAL ELECTRICAL SUPPLY ooMPaNY, or WASHINGTON, remium or conun- IBIL, A CORPORATION OF VIRGINLL.

RADIO RECEIVING APPARATUS.

Application filed October 4, 1927. Serial No. 223,903.

My invention relates broadly to radio receiving apparatus and more particularly to the system of mounting high frequency trans former apparatus in radio recelvmgsystems.

One of the objects of my invention is to provide a practical construction of radio receiving apparatus having interchangeable radio frequency coupling transformers con nected between the input and output circuits of the amplification stages comprising the high frequency amplifying system of the radio receiver.

Another object of my invention is to pro vide a construction of high frequency conpling transformer which may be mounted 1n the radio receiving apparatus by a movement of the transformer horizontally through a panel structure adjacent which the receiving apparatus is arranged.

rovide a construction of coupling transormer for the high frequency amplification circuits of a radio receiving system wherein guiding means is provided for horizontally N guiding a coupling transformer into the receivin apparatus from the front of a panel behin which the receiving apparatus 1s mounted, to effect interchangeability of the coupling transformer with respect to the cir- ;o cuits of the receiving apparatus from the front of the apparatus without raising the hinged cover of the apparatus or without moving the receiving apparatus bodily from the shielded casing in which the apparatus is normally housed.

M invention will be more fully understoo from the specification hereinafter following by reference to the accompanying drawings, in which:

Figure 1 is a front view of a receiving ,apparatus panel showing the transformer apparatus arranged for removal from or replacement through the front of the panel; Fig. 2 is a plan view illustrating the arrange-. ment of the guiding means which extend horizontally from the rear of'the vertical panel structure enabling the transformer device to be inserted into the receiving apparatus from the front of the panel in a horizontal direc- Still another object of my invention is to tus; Fig. 6 shows the transformer apparatus in a position about to be removed from the front of the receiving apparatus panel; and Fig. 7 is a-perspective view of a radio receiving apparatus showing the mounting of the transformer apparatus with respect to the radio receiver and the manner in which 4 the transformer equipment may be inserted into the apparatus or removed therefrom through the front of the panel.

Heretofore in the art, it has been proposed to arrange the coupling transformers between the input and output circuits of an amplification system in such manner that they may be readily removed from the inter-stage coupling circuits for the insertion of other transformers having different frequency ranges. Heretofore, receivin apparatus has been arranged within a ca inet structure in such manner that access to the coupling transformers can readily be had by removing the apparatus from the cabinet structure or removing a part of the cabinet structure from the apparatus.

By my invention I provide an arrangement whereby transformer equipment may be inserted into the radio receiver through the front of the receiving apparatus panel with contacts arranged interiorly of the receiving apparatus to register with pins carried by the transformer equlpment enabling trans-- formers of a particular frequency characteristic to be readily inserted into the apparatus and connected with the interstage coupling circuit for operating the amplification system over the desired frequency range.

My invention provides a construction of transformer guiding means'extending perpendicular to the front panel structure of the receiving apparatus to a position in the rear of the panel structure and carrying contacts by which connection may be established with the input and output circuits of the electron tubes in the receiving apparatus which constitute the amplification system.

Referring to the drawings in more detail, reference character 1 designates the front panel of the receiving apparatus structure which is apertured to receive the high frequency transformer. system constructed in cylindrical form as represented by reference character 2. The panel structure 1 is metal. An auxiliary panel constructed of insulated material extends parallel to panel 1 and spaced from the rear thereof as shown in Fig. 2. The auxiliary panel 3 has an aperture corresponding to the aperture in panel 1 enabling the transformer casing 2 to pass freely therethrough. Three insulated guide members 4 are mounted on bracket members 5 secured to panel structure 3 and serve as guides for the cylindrical casing 14 of the transformer 2. The guides 4 extend from the rear of panel structure 1 to the insulated panel structure 6. The panel structure 6 carries a plurality of socket devices 7 which connect to the input and output circuits of the electron tube amplifleaon apparatus which is mounted within the radio receiver. Resilient pin members 8 are carried by the insulated end panel 21 of the transformer casing 14. The pins 8 terminate in binding posts 9 within the casing, which post-s connect with the primary and secondary windings of the transformer system represented at 11 and 12. The primary and secondary windings 11 and 12 are supported on the coil form 10 by means of spacer members 18 and connecting members 17 extending from the insulated panel 21. The casing 14 is secured to the end panel 21 by means of screw members 15. The front of the transformer apparatus at 2 is secured to the casing 14 by means of screw members 16. In order to accurately control the movement of the pins 8 with respect to the sockets 7 a guide lug 19 is provided in the end of the transformer casing. A groove 20 is provided in the guide 4 as illustrated, and lug 19 extends therein throughout the course of travel of the transformer apparatus in the course of its movement from the exterior of the panel 1 to a position Where pins 8 enter the sockets 7.

It will be observed that the equipment is extremely compact in its arrangement inasmuch as the several circuits of the amplifier terminate at the sockets 7 on terminal board 6, and the operator may choose any desired coupling transformer having the required frequency range and readily slide the transformer through the front of the panel 1 to a position where connection is established between the pin terminals 8 and the sockets 7.

My invention has been found to be extremely practical and successful in its operation and practical for manufacture on a quantity production basis.

Vhile I have described preferred embodiments of my invention, I desire that it be understood that modifications may be made and that no limitations are intended other than are imposed by the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is as fol lows:

1. In a transformer mounting for radio receiving apparatus a panel structure apertured to receive a transformer through the front thereof, an auxiliary panel structure extending parallel to said aforementioned panel structure and correspondingly apertured to permit the insertion or removal of the transformer therethrough, and a plurality of guide members carried by said auxiliary panel structure and extending substantially at right angles to said aforementioned panel structure adjacent the aperturcd portion thereof for guiding said transformer into or out of said radio receiving apparatus.

2. In a radio receiving apparatus a inounting for a radio frequency coupling transformer comprising an apertured panel structure for permitting the insertion or removal of a radio frequency coupling transformer from the front thereof, a panel structure extending'in spaced relationship to said aforementioned panel structure, a plurality of longitudinally extending guides secured to said last mentioned panel structure abutting at their ends with said first mentioned panel structure and operating to guide a radio frequency coupling transformer to a position inside of said radio receiving apparatus.

3. In a radio receiving apparatus a mounting for a radio frequency coupling transformer comprising a panel apertured to permit the insertion or removal of a radio frequency coupling transformer therethrough, an auxiliary panel extending in spaced relationship in the rear of said aforementioned panel and correspondingly apertured to permit the passage of said radio frequency coupling transformer therethrough, a plurality of longitudinal guides carried by said auxiliary panel, a terminal board carried by said guides, sockets disposed on said terminal board and pin members carried by said transformer and arranged to establish connection with said sockets when said transformer is moved in a horizontal direction from a position outside of said radio receiving apparatus to a position Within said radio receiving apparatus.

4. In a radio receiving apparatus a mounting for a radio frequency coupling transformer comprising an apertured panel structure constituting the front of a radio receiving apparatus, an auxiliary panel structure extending in s aced parallel relationship with respect to the front of said radio receiving apparatus and having an aperture corresponding to the aperture in said first mentioned panel structure, insulated strip members carried by said auxilia panel structure and extending inop osite irections therefrom to a osition in abutment with the rear of said rst mentioned panel structure and a terminal board carried by the opposite ends of said strip members, said terminal board having contact devices thereon for establishing conneotion with corresponding contact-s carried by said transformer when the transformer is moved along said strip members from the front of said first mentioned panel structures.

5. Radio receivin mounting for a ra io frequency coupling transformer comprising a panel apertured to permit the insertion or removal of a. radio freuenoy couplin transformer from the front t ereof, a pane structure spaced from said aforementioned panel structure and apertured in alignment with said aforementioned panel, strip members carried by said second men tioned panel structure exteriorly of the apertured portions of said panel structures, a terminal boa-rd carried by said strip members and having sockets thereon positioned in alignment With pin terminals carried by said transformer, and means protruding from said transformer in sliding engagement with one of said strip members for guiding said transformer into or out of said radio receiving apapparatus having a paratus and establishing connection between selected pin terminals on said transformer and particular sockets on said terminal board.

6. In a radio receiving apparatus a panel.

tionship with respect to each other and car-.,

ried by said second mentioned panel structure, a terminal board supported on the ends of said strip members and havin sockets thereon, said transformers having pin terminals extendin from the rear thereof for enagement wit the sockets on said terminal oard and a lug member extending from said transformer and en aging a groove in one of said strip members or guiding the pin terminals of said transformer longitudinally into or out of engagement with the sockets on said terminal board and preventing rotative movement of said transformer.

In testimony whereof I afiix my signature.

SAMUF-L TAYLOR soHoFIELD. 

